The present invention relates to the ore mining industry and, more particularly, to machines for discharging crushed rock.
The machine of the present invention is of particular advantage for loading of blasted rock in mines in which loose rock is released from a stope place through an outlet opening to a mine working floor where the machine is located. Crushed rock flows by gravity into an operating unit of the machine, is caught, extracted and transferred to the discharge area by travelling aprons of a conveyor.
Known in the art are loading machines, the operating unit of which is made in the form of a bucket, pan, shovel, rotating gathering heads, etc. These are located adjacent to a conveyor, with the operating unit dug-in under crushed rock along a straight path. The bucket, pan, shovel, rotating gathering heads, etc., transport the rock to the joined conveyor section which carries it to the discharge area. The crushed rock is hauled to the conveyor by virtue of mechanical movements or jigging of the bucket, pan, or shovel toward the face, with the operating unit deepened only slightly under the broken rock to be loaded during the operating procedure.
The construction and operating principle of the operating units of the prior-art machines do not provide for full utilization of gravity of crushed rock for self-loading of the conveyor, and great potentialities of travelling aprons in catching and extracting crushed rock from the pile cannot be fully exploited.
These disadvantages are substantially obviated in loading machines constructed in accordance with the USSR inventor's certificate No. 235697, class E 21f, 13/00.
The machines comprise a carriage and a swinging body with a boom in the form of two parallel brackets connected to the body by means of hydraulic jacks a hinge, and allowed to turn in the vertical plane for setting the boom to the transport and operating positions. Suspended from the inner sides of the bracket by means of a shaft is an operating unit capable of turning in the vertical plane and serving to dig-in under loose rock on the floor, with the operating unit composed of two sector-shaped guide plates furnished with arched rear edges and interconnected by a beam in the upper section, and by a wedge cross-bar in the lower section, and with a recess made in the rear wall. Placed beside the recess, and hinged to the guide plates, is a driven roller of the conveyor comprising a hinge-jointed intake section for catching and extracting of crushed rock located above the section after the section is deepened, and a discharge section for hauling the rock to the discharge area, with the latter section installed on rollers and allowed to move horizontally within the body of the machine.
In order to remove the stresses acting on the carriage during turrning motion of the operating unit dug into crushed rock, and to improve adhesion between the machine and the floor, the boom is fitted with supports capable of displacement in the vertical plane, and of contact by their noses with the mine working floor.
In the machines, the construction and method of attaching of the operating unit, provide for digging-in the conveyor under the loose rock pile to a depth sufficient for effective self-loading, and permit setting the operating unit in a position, wherein broken rock can be gathered and extracted. Under favorable conditions, the machines develop a loading rate exceeding that of any other known loading machines operating under similar conditions. However, sometimes the efficiency of the machines is not as high. This is ascribed to the fact that flow of rock to the conveyor is periodically interrupted because large lumps of rock cause choking in the process of rock flow from the outlet opening. Commonly, the chokes take place in the area where the lumps are released from the outlet opening or in the area where the conveyor intake section is immersed under the pile.
Chokes in these areas are eliminated using the operating unit which disturbs the rest points and cohesion of the choked rock. For this purpose, the operating unit dug deep into the pile is turned in the vertical plane several times if required, or is retracted from under the pile to the initial extreme rear position, and then immersed again under the crushed rock in any given place along the loading area. The conveyor can be switched on or off as required, but in both cases the operating unit does not accomplish the principal work, i.e. loading, or is operating with low efficiency.
Besides, the efficiency of the machines depends on the incline of the conveyor preset in the extreme rear or extreme forward position, and also on the size of the inlet hole in the operating unit located between the guide plates, on the beam associated with the guide plates, and on the conveyor intake section. The smaller the incline of the conveyor in these positions, or in intermediate positions, and the larger the area of the inlet hole, the higher the capacity of the conveyor in gathering and extracting crushed rock from under the pile and, hence, the higher the flow capacity of the operating unit inlet hole, including the capacity to admit large-lumped rock. In the prior-art machines, the overall length and height thereof are reasonably small for mine workings, but the incline of the intake section of the conveyor in the operating positions is practically constant and inadmissible for use of belt conveyors, and close to admissible for use of flight conveyors, in respect to the extraction factor, for use of chain conveyors, because the conveyor intake and discharge section connecting hinge is arranged and displaced horizontally in guides fitted into the machine body. In addition, location of the hinge joint of the conveyor intake and discharge sections in the horizontal guide influences the position of the travelling apron with the operating unit placed to the extreme forward position. The conveyor in above machines is always kinked in the area of the hinge joint, which affects the working conditions of the conveyor.
Apart from clearing the above-mentioned chokes, the machines accomplish other auxiliary operations before the principle operating procedure, i.e. loading, may be started. The machines accomplish cleaning and mucking of the mine working floor when transferred from one face to another, sweep the rock thrown over the working at explosion, and shape piles or rock directly in the face to permit digging in the operating unit to a desired depth. For this purpose, the operating unit and machine itself must be maneuvered along the width of the working and the loading area. When the operating unit makes turns, and the machine is moved on the carriage in the required direction, large lumps of rock getting under the carriage must be removed by additional maneuvers of the machine and operating unit since the width of the area cleaned by the machine in a single run is not wider than the width of the operating unit. The portions of crushed rock raked in one run are rather small and there are no provisions for feeding crushed rock to the conveyor intake section from the sides of the conveyor. Hence, the efficiency of the machine in auxiliary operations is low. As a consequence, the machine suffers from the following disadvantages.
The principle disadvantage resides in the fact that the clearing of stoppages caused by lumps of loose rock in the supply of rock to the conveyor intake section from the outlet opening, is accomplished by the operating unit alone, with the result that the efficiency of the machine during work time goes down. There are no provisions for effective control of flow of crushed rock released from the outlet opening, and for simultaneous clearing of the chokes independently of the operating unit without detaching it from the principal rock handling procedure.
Another disadvantage resides in the fact that the operating unit of the machine is to be maneuvered redundantly along the loading area for the purpose of loading the conveyor intake section, with loose rock on both sides of the section during the principle operation, as well as during auxiliary operations described above.
Still another disadvantage is that the carriage of the machines is not protected against the ingress of large lumps of rock under the bottom. In order that the machine be moved in the desired direction, a plurality of maneuvers must be accomplished by the operating unit and by the machine for removing large lumps from under the carriage.
A further disadvantage, inherent in the machines, resides in the fact that during movement of the machine in the required direction at mucking of the mine working floor, only small portions of crushed rock are accumulated in front of the operating unit, so that much time is required for cleaning large areas.
Another disadvantage lies in the fact that owing to a low height clearance between the operating unit attachment shaft and the conveyor intake section, the flow capacity of the operating unit inlet hole between the operating unit shaft, conveyor and guide plates is low, with the result that the efficiency of the machine falls.
Still another disadvantage resides in that the rate at which the conveyor gathers and extracts crushed rock from under the pile is too low, because the incline of the conveyor intake section in the horizontal plane is nearly equal to the limit tolerance, with respect to the extraction factor, when the operating unit is in the extreme forward position, and also because the incline cannot be reduced with the existing limited height and length of the machine (due to horizontal displacements of the hinge joints of the conveyor sections).
A further disadvantage lies in the kinking of the conveyor in the area of the hinge joint between the inclined and horizontal sections when the conveyor is set to the extreme forward operating position, i.e., to the high-duty position, with the result that the operating conditions of the conveyor are impaired.
It is therefore a primary object of the present invention to provide a modified loading machine free from the above mentioned disadvantages, wherein the gravity of crushed rock released from the stope area is turned to useful account, with crushed rock gathered, extracted, and transferred to the unloading area by the conveyor, with the machine thus enabled to remove rock from under the outlet opening at a still higher rate. Therewith, thee overall dimensions of the machine of the present invention do not exceed the overall dimensions of loading machines used for the same purposes.
An additional object of this invention is to provide a machine wherein the flow rate may be accelerated and, among other things chokes in the area of the outlet opening and conveyor intake section may be eliminated without repeated detachment of the operating unit from the principle work for clearing purposes.
A further object of the present invention is to provide a machine wherein there are provisions for feeding crushed rock from both sides of the conveyor to the intake section.
Still another object of the present invention is to provide a machine capable of bulldozing a wide area in one run at cleaning of mine workings without redundant manipulations of the operating unit and machine along the loading area with the running gear protected against the ingress of large lumps of broken rock under the bottom.
The invention is also aimed at providing a machine with a higher flow rate of the operating unit inlet hole formed between the unit attachment shaft, side guide plates and conveyor intake section, and, hence, with a higher efficiency and capacity of loading crushed rock, including large lumps.
Yet another object of the present invention is to provide a machine highly efficient in extraction of loose rock with the conveyor from under the pile.
The invention is also aimed at providing a machine having facilities for easier operation of the conveyor which is placed at loading to the extreme forward operating position wherein the rate of extraction of crushed rock from under the pile is maximum.